The very flat line from the beginning shows how the usage looked like when I left Zimbra overnight, doing nothing (!). The two "mountains" towards the end show two attempts to again install Zimbra. Each time the consumptions was below 4gb.

The below depicts in detail how the reconfiguration "worked". The servers were restarted in half-way, but then again, after servers started the memory usage went through the roof.

I love Zimbra. It's a fantastic system, but during the past few days I installed Zimbra at least 20 times, spending 12+ hours a day. Please, can anyone advise me on how to make it work by using only 2gb at the very maximum for no more than 5 users?